Writing a Maven Tile

A Maven Tile is made up of a pom.xml and a tile.xml.

The pom.xml is a basic Maven project using the packaging type of tile, and the inclusion of the tiles-maven-plugin, along with release plugin configuration (often coming itself from a tile).

The POM would be minimal, only declaring the name, groupId, artifactId, version, description, and packaging (tile) attributes and generally only a declaration of the Maven Tiles plugin.

The tiles plugin will only have a configuration element defined when using other tiles (generally, you use at least one - a release tile).

pom.xml

<project>
  <groupId>io.repaint.maven</groupId>
  <artifactId>license-tile</artifactId>
  <version>1.1-SNAPSHOT</version>
  <packaging>tile</packaging>
  <description>Contains consistent license information.</description>
  <modelVersion>4.0.0</modelVersion>

  <build>
    <plugins>
      <plugin>
        <groupId>io.repaint.maven</groupId>
        <artifactId>tiles-maven-plugin</artifactId>
        <version>2.37</version>
        <extensions>true</extensions>
        <configuration>
          <filtering>false</filtering>
          <tiles>
            <tile>io.repaint.tiles:github-release-tile:[1.1, 2)</tile>
          </tiles>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

With the packaging tile, the plugin will look for the attached `tile.xml“, do some basic validation on it and attach it as an artifact.

When the <filtering> configuration item is specified as true - then standard Maven resource filtering for @project.version@ style references is applied to the tile.xml file prior to install/deploy.

tile.xml

<?xml version="1.0" encoding="UTF-8"?>
<project>
  <modelVersion>4.0.0</modelVersion>
  <licenses>
    <license>
      <name>The Apache Software License, Version 2.0</name>
      <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
      <distribution>repo</distribution>
    </license>
  </licenses>
</project>

Using Snapshots of Tiles

-SNAPSHOT versions of tiles work when installed into your local ~/.m2/repository, however - if you wish to use a published SNAPSHOT - you will need to declare a <repository> in your pom.xml that support SNAPSHOTs.

Review the introduction to repositories section on the Apache Maven website.

If you don’t wish to include <repository> definitions in your project source, declaring them in an activated <profile> in your ~/.m2/settings.xml file is a viable alternative.

📌 NOTE
This introduces an element of inconsistentcy/non-reproducability to your build and should be done with care.

Transcluding Tiles

A tile can define the tiles plugin if it wishes to cascade tile inclusion, or it can use the extended tile.xml syntax:

tile.xml

<?xml version="1.0" encoding="UTF-8"?>
<project>
  <modelVersion>4.0.0</modelVersion>
  <licenses>
    <license>
      <name>The Apache Software License, Version 2.0</name>
      <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
      <distribution>repo</distribution>
    </license>
  </licenses>

  <tiles>
    <tile>io.repaint.tiles:ratpack-tile:[1,2)</tile>
  </tiles>

</project>

Although this will appear to not validate when editing in an IDE, the tile plugin will strip off the tiles section when processing and use it directly.